Incandescent electeic lamp controller



(No Model.) 2 Sheets-Sheet 1.

J. J. FANNING.

INOANDESGENT ELECTRIC LAMP CONTROLLER No. 454,038. Patented June16,1891.

(No Model.) 2 Sheets-Sheet 2,

J. J. TANNING.

INGANDESGENT ELECTRIC LAMP CONTROLLER.

No. 454,038. Patented June 16,1891.

U ITED STATES PATENT OFFICE.

JOHN J. FANNING, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO JOHNBAIRSTOIV, OF SAME PLACE.

INCANDESCENT ELECTRlC-LAMP CONTROLLER.

SPECIFICATION forming part of Letters Patent No. 454,038, dated June 16,1891.

7 Application filed November 4, 1890- Serial No. 370,325. (No model.)

To all whom it may concern:

Be it known that I, JOHN J. FANNING, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a certain new and useful Improvement in Incandescent ElectricLamp Controllers, of which the following is a full, clear, concise, andexact description, reference being had to the accompanying drawings,forming a part of this specification.

Incandescent electric lamps have been found especially useful inconnection with scenic exhibitions on account of the softness of thelight and the fact that the lamps may be controlled as to number andbrilliancy with the greatest facility.

Incandescentlampshave been found of spe cial advantage in giving theeffects of sunrise and sunset on this account. The apparatus, however,for controlling the lamps either in separate groups or all together hasbeen cumbersome and expensive and far from satisfactory in itsoperation.

A special requirement of the apparatus for controlling and changing thebrilliancy of the lamps is that its action should be so uniform andgradual that there will be no abrupt changes in the light, so that theeffect may be the gradual change from light to darkness, which causesthe beholder such esthetic pleasure. Moreover, this gradual change inthe light must be as to speed under the control of the-manager.Therefore no fixed mechanical movementwould be suitable for the varyingscenic fluctuations or changes required upon the stage. I haveaccordingly devised a form of rheostat in oonnectionwvith incandescentelectric lamps with apparatus for ma nipulating the same eitherseparately with different groups of lamps or simultaneously to controlseveral groups, in order that the most artistic and pleasing effects inillumination may be readily obtained with apparatus which, though simpleand cheap, is durable and effective. The rheostat which I have devisedand which I consider the preferable form consists of wire wound about acylinder, which wire should be of less size or area in cross-section asit approaches the lower portion of the cylinder or the open end of thewire. Thus a coil of ordinary galvanized wire,

consistingof two hundred an d twenty-ninefeet of No. 7 wire, two hundredand twenty feet of No. 10 wire, and one hundred and ninety-four feet ofNo. 12 wire I have found sufficient to control a group of sixty-onesixteen-candle incandescent lamps,the pressure being one hundred andfifteenvolts. Each lamp taking about half an ampere would make thecapacityof the coil at the commencement thirty and one-half am peres.The whole coil when inserted would reduce the current about one-halfthatis, to about one-fourth of an ampere for each lamp. WVhen thus reduced,the lamp is practically put out, its filament appearing red and givingout not to exceed one candle-power of illumination. The rheostats mayconveniently be placed above the stage, and the brushes I preferablymount upon vertical standards at the sides of the coils. By means ofsuitable cords connected with the brushes the brushes may be raised andlowered to bring more or less of the resistance of the coil into thecircuit. Each brush should be provided with two cords, one connecteddirectly thereto and the other passing over a pulley above, so that onpulling down the cord attached directly to the brush-carrier the brushwill be lowered, whileon pulling down the other cord which passes overthe pulley the brush will be raised. I have sometimes used an endlesscord passing over a pulley, the brush being secured to one side of thecord.

My invention will be more readily understood byreference to theaccompanying drawings, in which Figure 1 is a view illustrative of fourgroups of incandescent lamps with rheostats, one for each group,connected therewith and means for separately or simultaneously movingthe brushes. Fig. 2 is a transverse vertical sectional view of the barswith which the rheostat-cords are connected and the guides for the same,as seen from section-line was of Fig. 1. Fig. 8 is a side elevation ofthe rheostat, with the endless cord connected with the brush for raisingand lowering the same. Fig. i is a front elevation thereof as seen fromsection-line y y of Fig. 3. Fig. 5 is a detailed side view of the brushmounted upon the upright rods or guides. Fig. 6 is a plan view thereof.Fig. 7 is a modification showing a screw operated by a crank for raisingand lowering the brush. Fig. 8 shows a modification of the coil of therheostat and the brush, the coil being surrounded by the brush orfrictional sliding contact-maker, which is adapted to be moved up anddown over the same. 7

Like parts are indicated by similar letters of reference throughout thedifferent figures.

The rheostat proper, as shown most clearly in Fig. 3, consists of wirea, wound upon a cylinder of insulating material, the differentconvolutions being separated from one another. If required, the lowerconvolutions may be of smaller wire than the upper convolutions. I havein practice found that three different sizes may be advantageouslyemployed in the same coil, the upper third of the coil being No. 7 wire,the next third or middle portion being of No. 10 wire, and the lowerportion being of No. 12 wire.

The brushproper b may consist of copper ribbons or strips foldedtogether, as shown, and constantly pressed against the side of the coilsupon the cylinder by springs c. The brush-holder d should be of metal,and is of course electrically connected with the brush.

The rods e, being also of metal, serve as one terminal for the loop orcircuit with which a group of lamps is connected. Theserods being placedvertically at the side of the cylinder serve as guides for the holder(I, mounted thereon. The cord f for moving the brush may be attached tothe holder at g. This cord passes over the sheave 72, mounted above thecylinder.

In Figs. 3 and 4 I have shown a wheel 1', with which the cord is infrictional engagement for operating the same. This wheel is providedwith a pinion, with which a segmentgear meshes, said segment-gear beingprovided with a handle for operating the same to turn the wheel 1; ineither direction.

In Figs. 1 and 2 the cord f of each of the rheostats is cut in two atthe bottom and provided with handles Zm. The handles Z may be consideredas connected each with that portion of the cord leading directly to thesliding contact-maker, while the other handles m are connected each withthat portion of its cord leading over the pulley h. Thus by pulling down011 any handle Z the brush of the corresponding rheostat will be loweredto introduce the coil of the rheostat into the cir- 5 cuit of aparticular group of lamps.

The bars 0 p are provided with handles Q 4. Thus by taking hold of thehandles Q r all the rheostats may be operated together.

As shown in Fig. '7, the brush-holder is tapped out to receive the screw3, which may be turned by a crank to raise and lower the brush.

Having thus described my invention, I claim as new and desire to secureby Letters Patent 1. The combination, witha group of incandescent lamps,of a rheostat consisting of wire wound upon the cylinder of insulatingmaterial, the different convolutions being separated from one anotherand the wire forming the lower portion or portions of the coil being ofless area in cross-section than the wire forming the upper portion ofthe coil, the vertical rods or guides c, with which one end of thecircuit is electrically connected, and the brush mounted thereon, saidbrush upon its inner surface conforming to the shape of the cylinder andbeing constantly pressed against the same by spring-pressure, with meansfor moving the brush up and down to gradually introduce the resistanceof the rheostat into the circuit, substantially as and for the purposespecified.

2. The resistance-coil a of a rheostat, consisting of convolutions ofbare wire, the different convolutions having the same diameter andplaced vertically, the wire forming the lower portion of the coil beingsmaller than the upper portion thereof, the upper end of the coil beingconnected with one end of a circuit containing incandescent lamps, incombination with the brush of sliding frictional contact-piece I),constantly pressed against the coil to come in contact with two or moreof the same, the guide upon which the brushcarrier ismountedelectrically connected with the other end of the circuit, and means foroperating the brush from below to raise and lower the same whileconstantly pressed against two or more of the convolutions of the coils,whereby the resistance of the circuit containing the lamps may begradually increased to reduce the current about onehalf and thereby topracticallyextinguish the lamps, substantia ly as and for the purposespecified.

In witness whereof I hereunto subscribe my name this 1st day ofNovember, A. D. 1890.

JOHN J. FANNING. lVitnesses:

GEORGE P. BARTON, ELLA EDLER.

